The invention relates generally to an area specific event-driven information system and method used to monitor and track the location of items and relational events within a defined environment. Based on the movement and relation of the items in the environment, the invention performs user-specified actions to provide warnings and/or advice of authorized user defined proximities or to locate the items in the environment through the use of peripheral warning or communication devices.
Computer systems and technology employing electromagnetic frequencies, such as radio frequencies, to track the location of an object in an environment are generally known in the art. Many systems track items through area detection tracking. Area detection tracking commonly uses a single computer linked to radio frequency receivers placed periodically throughout a facility. The receivers attempt to locate tag transmitters placed on objects in the facility. The receivers employ a single antenna with a predetermined bandwidth. The larger the bandwidth the larger the potential tracking area to be covered but also the greater amount of energy required to operate the system. When the tag transmitter enters the bandwidth of a receiver, the receiver receives an identification code transmitted by the tag and relays the code to the computer. The computer then records the location of the object bearing the tag transmitter based on the location of the receiver in the facility that relayed the identification code.
Area detection tracking possesses many shortcomings. First, the systems typically provide insufficient coverage to track items to an acceptable resolution. Typically, area detection systems place receivers at stations or sites where objects are expected to be, such as the next station in a manufacturing process. The area detection system in those cases is merely a location verification system. The system reports that an item has arrived at its designated station, has arrived late, or at the incorrect station. However, the system has no ability to locate an item in a facility that has deviated from its designed course. Additionally, location verification systems are easy to intentionally avoid. Because receivers are only placed in particular locations with only a predetermined transmission receiving field, a deviant individual with knowledge of the system or receiver technology could remove items from the facility without detection.
Area detection tracking systems also do not provide any information on the direction in which an item bearing a transmitter has moved once it leaves the area-detection field of a receiver. These systems use point-to-point-tracking schemes. These schemes track the history of the movement of an object as it passes within the radio frequency fields of each receiver but cannot determine the direction of movement of an item. In such cases, the area detection systems provide information on the last recorded location of an object but provide no information on the object""s current location until the object passes within the radio frequency field of another receiver. In large facilities, such as manufacturing plants, office buildings, warehouses and hospitals, many paths of movement could branch from each area detection point making it difficult, if not impossible, to know the current location of an item when the item is not within the radio frequency area of a receiver.
In an attempt to overcome the shortcomings attributable to area detection systems, arrays of receivers are distributed in a grid pattern with the size of an detection area determined by the predetermined spacing of receivers based on the width of its radio frequency field. In a grid area detection scheme, radio frequency coverage of facility is increased closing the space between receivers thereby providing increased data collection and higher resolution for point-to-point trackingxe2x80x94the more receivers, the closer together, the greater the ability to plot the movement of the object throughout the facility.
Grid area detection systems carry serious disadvantages. First, grid systems are typically only used in smaller facilities with open floor plans such in manufacturing facilities for semiconductors, high-priced electronics or medical equipment. The grid area detection systems require many receivers in close proximity that make the capital and installation of such a system cost prohibitive in large facilities or in facilities with many corridors, rooms, multiple floors, and numerous points of ingress and egress. Second, grid detection systems are expensive to operate in terms of energy costs to run the numerous receivers. To minimize the operational costs of continuously running all receivers and transmitters, motion detection devices and circuits are employed in the facility to activate receivers only when objects are in motion in close proximity. However, the addition of motion detection technology to the system complicates operation of the detection efforts and adds additional installation and capital costs as well as complexities to the programming required to operate the system.
To overcome the disadvantages of the area detection methods, more complex tracking systems such as time-of-arrival and signal-strength methods have been developed to pinpoint and continuously track the location of an object within a facility. In such programs, receivers are placed strategically throughout a facility. As an object moves through a facility, the exact location of an object is determined by a time-of-arrival determination based on the amount of time it takes multiple receivers to receive a transmission from an item tagged with a transmitter. Based on the timing receipt of the signal from the multiple receivers, the computer can determine the location of items by correlating the time differential of signal receipt as a distance of the object from each receiver. Likewise, a signal-strength method determines the location of an object from the strength of its transmission received by multiple receivers. Here, signal-strength directly correlates with the distance of the object from the receiver, with the transmission signal being stronger the closer it is to a receiver.
The time-of-arrival and signal-strength methods also have disadvantages. Although these systems can determine the exact location of an object, they can only do so if the transmission from an object falls within the radio frequency area of at least three receivers. Accordingly, many receivers must be placed throughout a facility to provide sufficient coverage. Additionally, the tag transmitter assigned to an object often must transmit through walls, machinery and other obstructions that may absorb the transmission from the transmitter of the object introducing unpredictable levels of attenuation of signal strength or time delay in the receivers"" receipt of the signal. Obstructions may also deflect or reflect the signal of the transmitter projecting a false or ghost signal that does not correspond with the true location of the object. The time-of-arrival and signal-strength methods of tracking also involve complex transmitter and receiver circuitry and computer algorithms to determine the location of an item from the signal receipt by multiple receivers adding to the cost of the system and operational complexities. Because of these constraints, such systems typically are employed in small manufacturing facilities and offices where valuable items are often transported throughout the facility requiring continuous and detailed information on the items whereabouts.
Prior art radio frequency locating systems use single-frequency technology in locating systems. A limited number of other radio frequency locating systems use spread-spectrum radio communications in the high megahertz frequency ranges. Operation in the high frequency ranges is required to provide a larger bandwidth to increase the area of detection and the strength of the detection field over the area. Because of operation at these high frequencies, Federal Communications Commission licensing may be required to operate the system. Other systems may be operated in ranges not requiring licensing but may interfere with other systems in the facility such as telecommunication systems, computers, and equipment sensitive to the radio frequencies. Additionally, other systems in the facility may also emit radio frequencies in close proximity to the signal of the transmitter introducing noise that will project false locations or interfere with the calculations performed by the system to determine the location of an item.
Some low frequency detection systems are also known in the art. In these systems, transmitters operating in low frequency ranges transmit identification information from low range transmitters to receivers to log the location of a person or object. These systems because of the inaccuracy and stability of low-frequency transmissions require close proximity transmissions between the transmitter and the receiver. This transmission range is nominally two feet or less. Such systems may require passing or waving the transmitter next to or near the receiver or even a more active component of swiping the transmitter through a component linked to the receiver such as magnetic card reader or a scanning device. The close proximity required to record a transmission from the identification transmitter makes such systems unreliable to passively locate and monitor items in a facility.
Moreover, prior art radio frequency location systems are often ineffective in tracking the location of individuals in a facility. Individuals in a facility often find the continuous tracking of their location as invasive and will attempt to evade continuous monitoring of their location by avoiding receivers when and where possible. Intentional avoidance of receivers by individuals makes tracking the individuals as well as other objects that they may be transporting difficult and at times inaccurate.
Finally, prior art radio frequency location systems provide the limited role of documenting movement of an item or verifying its location in a facility. In some cases, the continuous monitoring of an item may be reviewed and evaluated to track down the last known location of an object or to determine that an item has deviated from its expected course in the facility. In such cases, reactive measures can be taken by personnel in the facility to either locate the object or attempt to learn why the item deviated from its expected path. However, prior art systems do not provide real-time responses to the movement of items in a facility to attempt to stop or curb the unauthorized movement of an item by communicating warnings to alert the mover of the item of the unauthorized activity, alerting security, and enabling users of the system to proactively locate an item in the facility. Prior art systems do not provide immediate response and action to the unauthorized movement or activity associated with an item. In the same course, known area detection systems are not coupled with third party communication and response devices in a facility to permit the system to utilize systems already present in the facility to aid in the location of an item or to immediately respond to unauthorized activities.
Large facilities, like hospitals, manufacturing plants, engineering facilities and the like cover large areas over multiple floors. Each of these facilities have items (inanimate objects as well as people) that need to be tracked. Items such as files, tools, and equipment are often missing, misplaced or even stolen. Items such as personnel, workers, patients and visitors become lost, wander into an unauthorized area, or leave a facility without others knowledge of these events. Much too often people commit unauthorized acts moving and misplacing equipment or removing an item from an environment altogether for their own personal gain or use. The cost associated with replacing stock or missing equipment and the time lost searching for misplaced items in a large facility can be enormous.
The instant invention is directed to an area-specific tracking and event-driven response system for tracking and monitoring items in a facility environment and providing actions in the environment in response to the current location or movement of an item. The system operates by assigning a configurable identification device, such as a badge or tag, embodied with a transmitter designed to emit a unique identification number assigned to each item. The identification device attaches to or is worn by each item to be tracked in the environment. The transmitter in each identification device operates through the use of near field radio frequencies that accurately sends the transmitted data through a transmission range of up to two meters from the transmitter without interfering with the operation of other electronic equipment in the environment or degrading the transmission because of the presence of other electronic equipment emitting similar radio frequencies.
The environment in which the system operates is divided into domains that correspond to discrete and sectional areas of the facility such as separate floors or departments. All items in a domain are tracked by a controller computer that manages the system functionalities in the domain. Each domain is further subdivided into zones. Zones typically encompass individual rooms, halls, closets, and other areas in a domain defined by a portal, a point of ingress or egress such as a doorway, elevator, escalator, or stairs, between zones in the domain or between domains themselves. A node computer assigned to track items in a zone connects to the controller computer for the domain that contains the zone.
A node computer connects to a receiver supported by a first and second antennas configuration generating adjacent and overlapping first and second receiving regions for receiving signals emitted from near field inductive or low frequency electromagnetic fields generated by the transmitter assigned to each item. These low frequency electromagnetic fields are generated in a pattern whereby an item passing through a portal must consecutively pass through the first and second receiving regions in a specific order. The order by which an item bearing an identification device passes through the first and second receiving regions at the portal determines the direction-of-travel of the item into or out of a zone. When a item passes through a receiving region, its identification device emits a signal of a first data packet which includes the unique identification number that is received through the first and/or second antenna corresponding to the receiving region through which the item has passed. The receiver sends to the node computer a second data packet which includes the unique identification number of the item and a direction-of-travel signal that corresponds to the antenna that received the transmission. The node computer verifies these signals.
The node computer operates software provided with the zone location of the node computers and receivers in the domain, the portal that separate zones and the receiver and node computer assigned to monitor each portal. From the repeated direction-of-travel information received by a node computer, the node computer determines the zone in which an item is located and the direction from which it entered the zone. The method of placing receivers at portalsxe2x80x94physically constrained points in a facilityxe2x80x94requires less receivers to determine the location of an item and removes the possibility that an item could evade the receivers thus providing a high tracking rate for the movement of an item. Additionally, the use of the dual adjacent receiving regions in a portal permits the transmitters to generate an electromagnetic field that must cover an area only as large as the portal permitting the use of less powerful transmitters and receiver configurations, and correspondingly lower energy and operational costs for the system. The dual adjacent low receiving regions also enable a determination of the direction-of-travel of an item as it moves through an environment enabling proactive responsive actions to be taken in response to or in anticipation to the movement of an item.
The node computer links with a controller computer sending information received from the transmitter such as the item""s identification number and other internally developed information like the direction of travel information and the time associated with the receipt of the transmitted information. In conjunction with the node computer, the controller computer determines and records the location of an item and the time the item entered that location in the environment. This process repeats each time an item bearing an identification device enters the receiving regions stationed about each portal. Controller computers maintain a record for each item that includes the location of the item as well as constraints to movement placed on an item, and actions to take in response to violations to the constraints to movement or violations in movement. Periodically, or upon the movement of an item through a portal, the controller computer compares the location of the item against the constraints to movement for that item. If a constraint is violated, the controller computer reviews the predefined actions to be taken if a violation in movement occurs. Such responses involve activating warning devices such as a user terminal or work station, electronic sign, a voice synthesizer, a monitor, or video camera to provide warning or alarms directed to the specific unauthorized movement of the item. Additionally, the controller computers continue to track the unauthorized movement of in item throughout the environment and provide the capability to activate warning devices based on the anticipated movement of the item through an environment based on direction-of-travel of an item through portals. The response and warning capabilities of the present invention provide more than mere information on the location of an item but also take user programmable active steps throughout the environment to warn of the unauthorized movement of an item and take anticipatory or reactive actions to attempt to curb the unauthorized movement of an item. The system also provides for the tracking of a person moving an item and responding to violation in movement of either the person or the item by providing warnings to that person directly to stop an unauthorized movement through warning devices and alarms available to the system and controlled by either the node computer or controller computer.
A central server coordinates controller computers in the environment. The central server maintains a database of records for all items not currently present in the environment or items in transit between domains. As an item moves from one domain to another, the controller computer monitoring the departing domain passes the record of the item to the central server when the item passes through a portal that marks an exit from the domain. The central server maintains the record for the item until the item passes through another portal permitting the item to enter a new domain, at which time the central server passes the record for the item to the controller computer monitoring the new domain.
The central server is also designed to connect to third computer systems through a system interface. The central server generates reports on the status and history of locations for each item and passes the reports through an interface to a computer network and databases maintained in the environment independently from the system. The central server also possesses the ability to interface with other third party communication systems existing independently in the environment such as computer networks, telecommunication networks, and pager systems. Through the third party communication systems, the central server may provide information to these systems or control these systems to provide additional alarms or warning regarding an unauthorized movement of an item. With this adaptation, the system is capable for utilizing communication systems already in place in an environment thereby alleviating the cost associated with providing new, duplicative systems or implementing new communications systems in the environment which people are unfamiliar with or not trained to use.